New filter restricting delegations in txpool

src/Nethermind/Nethermind.TxPool.Test/OnlyOneTxPerDelegatedAccountFilterTest.cs

@@ -0,0 +1,169 @@
+// SPDX-FileCopyrightText: 2024 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using Nethermind.Core;
+using Nethermind.Core.Specs;
+using Nethermind.Core.Test.Builders;
+using Nethermind.Crypto;
+using Nethermind.Db;
+using Nethermind.Evm;
+using Nethermind.Logging;
+using Nethermind.Specs.Forks;
+using Nethermind.State;
+using Nethermind.Trie.Pruning;
+using Nethermind.TxPool.Collections;
+using Nethermind.TxPool.Filters;
+using NSubstitute;
+using NUnit.Framework;
+using Org.BouncyCastle.Pqc.Crypto.Lms;
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Nethermind.TxPool.Test;
+internal class OnlyOneTxPerDelegatedAccountFilterTest
+{
+    [Test]
+    public void Accept_SenderIsNotDelegated_ReturnsAccepted()
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, Substitute.For<IReadOnlyStateProvider>(), new CodeInfoRepository(), new DelegationCache());
+        Transaction transaction = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.Accepted));
+    }
+
+    [Test]
+    public void Accept_SenderIsDelegatedWithNoTransactionsInPool_ReturnsAccepted()
+    {
+        IDb stateDb = new MemDb();
+        IDb codeDb = new MemDb();
+        TrieStore trieStore = new(stateDb, LimboLogs.Instance);
+        IWorldState stateProvider = new WorldState(trieStore, codeDb, LimboLogs.Instance);
+        stateProvider.CreateAccount(TestItem.AddressA, 0);
+        CodeInfoRepository codeInfoRepository = new();
+        byte[] code = [.. Eip7702Constants.DelegationHeader, .. TestItem.PrivateKeyA.Address.Bytes];
+        codeInfoRepository.InsertCode(stateProvider, code, TestItem.AddressA, Prague.Instance);
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, stateProvider, codeInfoRepository, new DelegationCache());
+        Transaction transaction = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.Accepted));
+    }
+
+    [Test]
+    public void Accept_SenderIsDelegatedWithOneTransactionInPoolWithSameNonce_ReturnsAccepted()
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        Transaction inPool = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        standardPool.TryInsert(inPool.Hash, inPool);
+        IDb stateDb = new MemDb();
+        IDb codeDb = new MemDb();
+        TrieStore trieStore = new(stateDb, LimboLogs.Instance);
+        IWorldState stateProvider = new WorldState(trieStore, codeDb, LimboLogs.Instance);
+        stateProvider.CreateAccount(TestItem.AddressA, 0);
+        CodeInfoRepository codeInfoRepository = new();
+        byte[] code = [.. Eip7702Constants.DelegationHeader, .. TestItem.PrivateKeyA.Address.Bytes];
+        codeInfoRepository.InsertCode(stateProvider, code, TestItem.AddressA, Prague.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, stateProvider, codeInfoRepository, new DelegationCache());
+        Transaction transaction = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.Accepted));
+    }
+
+    [Test]
+    public void Accept_SenderIsDelegatedWithOneTransactionInPoolWithDifferentNonce_ReturnsOnlyOneTxPerDelegatedAccount()
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        Transaction inPool = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        standardPool.TryInsert(inPool.Hash, inPool);
+        IDb stateDb = new MemDb();
+        IDb codeDb = new MemDb();
+        TrieStore trieStore = new(stateDb, LimboLogs.Instance);
+        IWorldState stateProvider = new WorldState(trieStore, codeDb, LimboLogs.Instance);
+        stateProvider.CreateAccount(TestItem.AddressA, 0);
+        CodeInfoRepository codeInfoRepository = new();
+        byte[] code = [.. Eip7702Constants.DelegationHeader, .. TestItem.PrivateKeyA.Address.Bytes];
+        codeInfoRepository.InsertCode(stateProvider, code, TestItem.AddressA, Prague.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, stateProvider, codeInfoRepository, new DelegationCache());
+        Transaction transaction = Build.A.Transaction.WithNonce(1).SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.MoreThanOneTxPerDelegatedAccount));
+    }
+
+    private static object[] EipActiveCases =
+    {
+        new object[]{ true, AcceptTxResult.MoreThanOneTxPerDelegatedAccount },
+        new object[]{ false, AcceptTxResult.Accepted},
+    };
+    [TestCaseSource(nameof(EipActiveCases))]
+    public void Accept_Eip7702IsNotActivated_ReturnsExpected(bool isActive, AcceptTxResult expected)
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(isActive ? Prague.Instance : Cancun.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        Transaction inPool = Build.A.Transaction.WithNonce(0).SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        standardPool.TryInsert(inPool.Hash, inPool);
+        IDb stateDb = new MemDb();
+        IDb codeDb = new MemDb();
+        TrieStore trieStore = new(stateDb, LimboLogs.Instance);
+        IWorldState stateProvider = new WorldState(trieStore, codeDb, LimboLogs.Instance);
+        stateProvider.CreateAccount(TestItem.AddressA, 0);
+        CodeInfoRepository codeInfoRepository = new();
+        byte[] code = [.. Eip7702Constants.DelegationHeader, .. TestItem.PrivateKeyA.Address.Bytes];
+        codeInfoRepository.InsertCode(stateProvider, code, TestItem.AddressA, Prague.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, stateProvider, codeInfoRepository, new DelegationCache());
+        Transaction transaction = Build.A.Transaction.WithNonce(1).SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void Accept_SenderHasPendingDelegation_ReturnsPendingDelegation()
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        DelegationCache pendingDelegations = new();
+        pendingDelegations.IncrementDelegationCount(TestItem.AddressA, 0);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, Substitute.For<IReadOnlyStateProvider>(), new CodeInfoRepository(), pendingDelegations);
+        Transaction transaction = Build.A.Transaction.WithNonce(0).SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.PendingDelegation));
+    }
+}

src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.cs

@@ -1770,6 +1770,95 @@ public void SubmitTx_CodeIsNotDelegationAndDelegation_DelegationIsAccepted((byte
             result.Should().Be(testCase.expected);
         }
 
+        [Test]
+        public void Delegated_account_can_only_have_one_tx()
+        {
+            ISpecProvider specProvider = GetPragueSpecProvider();
+            TxPoolConfig txPoolConfig = new TxPoolConfig { Size = 30, PersistentBlobStorageSize = 0 };
+            _txPool = CreatePool(txPoolConfig, specProvider);
+
+            PrivateKey signer = TestItem.PrivateKeyA;
+            _stateProvider.CreateAccount(signer.Address, UInt256.MaxValue);
+            byte[] delegation = [.. Eip7702Constants.DelegationHeader, .. TestItem.AddressC.Bytes];
+            _stateProvider.InsertCode(signer.Address, delegation.AsMemory(), Prague.Instance);
+
+            Transaction firstTx = Build.A.Transaction
+                .WithNonce(0)
+                .WithType(TxType.EIP1559)
+                .WithMaxFeePerGas(9.GWei())
+                .WithMaxPriorityFeePerGas(9.GWei())
+                .WithGasLimit(GasCostOf.Transaction)
+                .WithTo(TestItem.AddressB)
+                .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
+
+            AcceptTxResult result = _txPool.SubmitTx(firstTx, TxHandlingOptions.PersistentBroadcast);
+            result.Should().Be(AcceptTxResult.Accepted);
+
+            Transaction secondTx = Build.A.Transaction
+                .WithNonce(1)
+                .WithType(TxType.EIP1559)
+                .WithMaxFeePerGas(9.GWei())
+                .WithMaxPriorityFeePerGas(9.GWei())
+                .WithGasLimit(GasCostOf.Transaction)
+                .WithTo(TestItem.AddressB)
+                .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
+
+            result = _txPool.SubmitTx(secondTx, TxHandlingOptions.PersistentBroadcast);
+
+            result.Should().Be(AcceptTxResult.MoreThanOneTxPerDelegatedAccount);
+        }
+
+        [TestCase(true)]
+        [TestCase(true)]
+        public void Tx_with_pending_delegation_is_rejected_then_is_accepted_after_delegation_removal(bool withRemoval)
+        {
+            ISpecProvider specProvider = GetPragueSpecProvider();
+            TxPoolConfig txPoolConfig = new TxPoolConfig { Size = 30, PersistentBlobStorageSize = 0 };
+            _txPool = CreatePool(txPoolConfig, specProvider);
+
+            PrivateKey signer = TestItem.PrivateKeyA;
+            _stateProvider.CreateAccount(signer.Address, UInt256.MaxValue);
+
+            EthereumEcdsa ecdsa = new EthereumEcdsa(_specProvider.ChainId);
+
+            Transaction firstTx = Build.A.Transaction
+                .WithNonce(0)
+                .WithType(TxType.SetCode)
+                .WithMaxFeePerGas(9.GWei())
+                .WithMaxPriorityFeePerGas(9.GWei())
+                .WithGasLimit(100_000)
+                .WithAuthorizationCode(ecdsa.Sign(signer, specProvider.ChainId, TestItem.AddressC, 0))
+                .WithTo(TestItem.AddressB)
+                .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
+
+            AcceptTxResult result = _txPool.SubmitTx(firstTx, TxHandlingOptions.PersistentBroadcast);
+            result.Should().Be(AcceptTxResult.Accepted);
+
+            Transaction secondTx = Build.A.Transaction
+                .WithNonce(0)
+                .WithType(TxType.EIP1559)
+                .WithMaxFeePerGas(9.GWei())
+                .WithMaxPriorityFeePerGas(9.GWei())
+                .WithGasLimit(GasCostOf.Transaction)
+                .WithTo(TestItem.AddressB)
+                .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
+
+            if (withRemoval)
+            {
+                _txPool.RemoveTransaction(firstTx.Hash);
+
+                result = _txPool.SubmitTx(secondTx, TxHandlingOptions.PersistentBroadcast);
+
+                result.Should().Be(AcceptTxResult.Accepted);
+            }
+            else
+            {
+                result = _txPool.SubmitTx(secondTx, TxHandlingOptions.PersistentBroadcast);
+
+                result.Should().Be(AcceptTxResult.AlreadyKnown);
+            }
+        }
+
         private IDictionary<ITxPoolPeer, PrivateKey> GetPeers(int limit = 100)
         {
             var peers = new Dictionary<ITxPoolPeer, PrivateKey>();

src/Nethermind/Nethermind.TxPool/AcceptTxResult.cs

@@ -95,6 +95,16 @@ namespace Nethermind.TxPool
         /// </summary>
         public static readonly AcceptTxResult MaxTxSizeExceeded = new(16, nameof(MaxTxSizeExceeded));
 
+        /// <summary>
+        /// Only one tx is allowed per delegated account. 
+        /// </summary>
+        public static readonly AcceptTxResult MoreThanOneTxPerDelegatedAccount = new(17, nameof(MoreThanOneTxPerDelegatedAccount));
+
+        /// <summary>
+        /// There is a pending delegation in the tx pool already
+        /// </summary>
+        public static readonly AcceptTxResult PendingDelegation = new(18, nameof(PendingDelegation));
+
         /// <summary>
         /// The node is syncing and cannot accept transactions at this time.
         /// </summary>

src/Nethermind/Nethermind.TxPool/Collections/SortedPool.cs

@@ -530,6 +530,14 @@ public bool TryGetBucketsWorstValue(TGroupKey groupKey, out TValue? item)
             return false;
         }
 
+        public bool BucketEmptyExcept(TGroupKey groupKey, Func<TValue, bool> predicate)
+        {
+            using var lockRelease = Lock.Acquire();
+            if (_buckets.TryGetValue(groupKey, out EnhancedSortedSet<TValue>? bucket) && bucket.Count > 0)
+                return bucket.Any(predicate);
+            return true;
+        }
+
         protected void EnsureCapacity(int? expectedCapacity = null)
         {
             expectedCapacity ??= _capacity; // expectedCapacity is added for testing purpose. null should be used in production code

src/Nethermind/Nethermind.TxPool/DelegationCache.cs

@@ -0,0 +1,64 @@
+// SPDX-FileCopyrightText: 2024 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using Nethermind.Core;
+using Nethermind.Int256;
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Nethermind.TxPool;
+internal sealed class DelegationCache
+{
+    private readonly ConcurrentDictionary<UInt256, int> _pendingDelegations = new();
+
+    public bool HasPending(AddressAsKey key, UInt256 nonce)
+    {
+        return _pendingDelegations.ContainsKey(KeyMask(key, nonce));
+    }
+
+    public void DecrementDelegationCount(AddressAsKey key, UInt256 nonce)
+    {
+        InternalIncrement(key, nonce, false);
+    }
+    public void IncrementDelegationCount(AddressAsKey key, UInt256 nonce)
+    {
+        InternalIncrement(key, nonce, true);
+    }
+
+    private void InternalIncrement(AddressAsKey key, UInt256 nonce, bool increment)
+    {
+        UInt256 addressPlusNonce = KeyMask(key, nonce);
+
+        int value = increment ? 1 : -1;
+        var lastCount = _pendingDelegations.AddOrUpdate(addressPlusNonce,
+            (k) =>
+            {
+                if (increment)
+                    return 1;
+                return 0;
+            },
+            (k, c) => c + value);
+
+        if (lastCount == 0)
+        {
+            //Remove() is threadsafe and only removes if the count is the same as the updated one
+            ((ICollection<KeyValuePair<UInt256, int>>)_pendingDelegations).Remove(
+                new KeyValuePair<UInt256, int>(addressPlusNonce, lastCount));
+        }
+    }
+
+    private static UInt256 KeyMask(AddressAsKey key, UInt256 nonce)
+    {
+        //A nonce cannot exceed 2^64-1 and an address is 20 bytes, so we can pack them together in one u256
+        ref byte baseRef = ref key.Value.Bytes[0];
+        return new UInt256(Unsafe.ReadUnaligned<ulong>(ref baseRef),
+          Unsafe.ReadUnaligned<ulong>(ref Unsafe.Add(ref baseRef, 8)),
+          Unsafe.ReadUnaligned<uint>(ref Unsafe.Add(ref baseRef, 16)),
+          nonce.u1);
+    }
+}

src/Nethermind/Nethermind.TxPool/Filters/MalformedTxFilter.cs

@@ -19,7 +19,8 @@ internal sealed class MalformedTxFilter(
         public AcceptTxResult Accept(Transaction tx, ref TxFilteringState state, TxHandlingOptions txHandlingOptions)
         {
             IReleaseSpec spec = specProvider.GetCurrentHeadSpec();
-            if (!txValidator.IsWellFormed(tx, spec))
+            ValidationResult result = txValidator.IsWellFormed(tx, spec);
+            if (!result)
             {
                 Metrics.PendingTransactionsMalformed++;
                 // It may happen that other nodes send us transactions that were signed for another chain or don't have enough gas.